Selectivity in photocatalysis by particulate semiconductors

TiO₂, Fe₂O₃, CuO, ZnO, ZnS, Nb₂O₅, MoO₃, CdO, CdS, Sb₂O₃, CeO₂, HgO, Pb₂O₃, PbO₂ and Bi₂O₃ microparticles exhibit band gap excitation with UV-A light but they are selective to photodegrade phenols. While TiO₂ anatase and ZnO photocatalyze the degradation of phenol, o-aminophenol, m-aminophenol, p-aminophenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-nitrophenol, p-nitrophenol, o-cresol, m-cresol, p-cresol, catechol, resorcinol and quinol, MoO₃ does not photodegrade any of the fifteen phenols. Fe₂O₃, CuO, ZnS, Nb₂O₅, CdO, CdS, Sb₂O₃, CeO₂, HgO, Pb₂O₃, PbO₂ and Bi₂O₃ are selective in photodegrading the fifteen phenols; however, the phenols get adsorbed over all sixteen particulate semiconductors.